This invention relates to a method and apparatus for marshalling sheets including for example sheet transfer apparatus for transferring a selected sheet or sheets, e.g. of glass, from a conveyor carrying a plurality of such sheets extending transversely across it to a position at one side of the conveyor. Such apparatus is particularly but not exclusively adapted for use in conjunction with an apparatus for snapping a sheet of glass along one or more score lines extending along the sheet, as described in our U.S. Pat. No. 4,131,222. The latter apparatus includes a plurality of conveyors diverging away from one another along their direction of advance, so that the result of snapping a sheet of glass along one or more score lines parallel to the direction of advance is to produce an array of sheet portions spaced apart from one another and extending transversely across the conveyor assembly. It is a particular object of the present invention to provide a method and apparatus capable of effecting selective transfer of sheets from such an array.
Arrangements are known for handling glass sheets in which a large sheet is conveyed longitudinally along a main conveyor and cut into two along a longitudinal line. The two separate sheets are then transferred onto side branch conveyors extending at right angles to the main conveyor and then the sheets may again be cut as desired along longitudinal lines. These further cut sheet portions may then be transferred onto further side leg conveyors parallel to the main conveyor. The operation may be repeated as many times as necessary by use of many side leg conveyors until the final sheet sizes are obtained on each of the side leg conveyors and fed to a respective stacker. However such an arrangement is wasteful of space, as well as cutting and inspecting equipment and personnel. Each time a sheet is conveyed onto a new branch conveyor separate scoring and/or snapping equipment is needed for that particular conveyor. The extensive array of conveyors inevitably extends over a large floor space and separate inspection personnel are required on each side leg leading to a stacker. Separate cullet collection facilities for collecting reject sheets are also needed for each side leg. Furthermore, in order to achieve economic use of such an extensive system of side leg conveyors, it is necessary to operate with relatively long runs on each of the sheet sizes provided by the system as substantial mechanical alterations are also needed to vary the cutting pattern used.